1. Field of the Invention
The present invention is related to a user interface of a computer system. More particularly, it is related to an efficient menu process in the display screen of an integrated I/O (input/output) device or the like which uses a transparent tablet and a liquid crystal display.
2. Prior Art
The conventional computer user interaction technique has been developed mainly on the basis of a bit map display and mouse (or tablet), and it is designed for user operation on the assumption that the whole screen is basically visible. A typical example of user interaction is to use a menu. This is a method in which choices such as commands are displayed on a bit map display and input by the use of a pointing device such as a mouse. There is a pull-down menu as shown in FIG. 1 in which the menu is hierarchical to improve usability. In this menu system, a menu bar is usually positioned in the upper portions of a display or window and the individual items are laterally arranged, and a pull-down menu is vertically displayed. Since a user generally scans the screen from top to bottom in a system using a mouse and a bit map display, such an arrangement between the menu bar and the pull-down menu is very efficient.
Owing to the advance of sensor and liquid crystal technologies, an integrated I/O device using a transparent tablet and a liquid crystal display has been developed, replacing the bit map display and mouse. This device is characterized in that an item now on display can be directly operated; the position of the item being displayed is coincident with that of the object to be operated. However, the direct use of the conventional pull-down menu system has the following problems.
(1) The menu items on the menu bar at the side of the arm having a pen are hidden. (See FIG. 2.) PA1 (2) The pull-down items are also hidden by the hand while they are being selected in the downward direction, even though the first item is in sight. (See FIG. 3.)
Incidentally, the patent references related to the present invention include the Published Unexamined Patent Application Nos. 254233/1987 and 205722/1988 official gazettes. Although these are to improve the conventional menu bar and pull-down menu scheme, the menu bar is laterally arranged at the top of the screen, and thus they are different from the present invention. In addition, a method for diagonally displaying a pull-down menu is disclosed in IBM Technical Disclosure Bulletin, Vol. 32, No.8, pp. 370-372, January 1990, but the menu bar is also laterally arranged at the top of the screen in this method.
Also in a user-friendly user interface, icons representing applications may be vertically lined up, for instance, at the right end of the screen (IBM AIX NextStep Environment/6000, sc23-2357, p. 2-29), but this is to display the frequently used applications in order for easy understanding, and thus pen input is not taken into consideration. Further, an application is merely initiated by selection of an icon in such interface, and a pull-down menu or the like is not further displayed.